Wk 2: joint & ligaments Flashcards
Arthrology & hip joint
Joint
union between two or more bones
Fibrous
Fibrous tissue joins the bones
Amount of movement depends on length of fibres
Suture (fibrous)
- Only found in the skull
- Bones are linked by short fibres of connective tissue
- Little to no movement
Joint classification
- Structure: fibrous, cartilaginous and synovial
- Amount of movement available: immobile, slightly mobile and freely mobile
Syndesmosis (fibrous)
- Forearm & leg
- Bones are linked by longer bands of connective tissue
- Very slightly mobile
Cartilaginous
Cartilage tissue joins the bones
Amount of movement depends on the type of cartilage
Symphysis or secondary cartilaginous
- A disc of fibrocartilage binds 2 bones together
- Found in the mid-line of the body
- Slightly mobile
First sternocostal joint (Synchondrosis)
- Very limited mobility
Synovial
Bones lined with cartilage (joint cavity)
Amount of movement depends on the shape of the joint
Synchondrosis or primary cartilaginous
- Found at epiphyseal plates (where bone growth occurs)
- Eventually completely ossify
- Epiphyseal line & immobile
Synovial joint classification
- Shape
- Degrees of freedom (uni, bi, multiaxial)
Joint axes (synovial)
- Anteroposterior: front to back
- Horizontal: side to side/left to right
- Longitudinal: vertical or along length of bone
Degrees of freedom (synovial)
Number of axes about which movement occurs
Uniaxial: one pair of movements
Biaxial: two pairs of movements
Multiaxial: three pairs of movements
Axis is perpendicular to the plane (of body) (synovial)
- Sagittal perpendicular to horizontal
- Coronal perpendicular to anteroposterior axis
- Transverse perpendicular to longitudinal axis
Movement axes and their movements possible (synovial)
- Longitudinal: rotation
- Anteroposterior: abduction/adduction and lateral flexion
- Horizontal: flexion/extension
Ligaments
bands of fibrous tissue that occur at joints
Ligament functions
- Act as a mechanical constraint
- Prevent undesired movement
- Permit limited amounts of desired movement
- Sensory: proprioception
Types of ligaments
- Intra-capsular: deep to capsule
- Capsular: re-enforces capsule
- Extra-capsular: away from capsule
Bursae
Fluid-filled sacs around many synovial joints: potential space
Function to reduce friction as structures slide on one another thus
Located between layers of muscles
Articular Discs
Fibrocartilage pads between the articular surfaces of some synovial joints
Functions of articular discs
- Shock absorbers
- Permit different movements to occur in the joint
- Aid mechanical fit between articular surfaces
- Restrain movement
- Assist lubrication
Active movement
Produced by muscle contraction
Passive movement
Produced by an external force
Passive movement types
Passive physiological: can also be produced actively
Passive accessory: the movement cannot be produced actively
Roll (roll spin glide)
one surface rolls across the other (contact of new parts of both surface)